低密度钢冶炼相关的熔体物理化学性质基础研究

In view of the fact that the thermophysical and thermodynamic data of the melts for the smelting of low-density steels are scarce and the related kinetic mechanism of the reaction between slags and metals is blurry, the fundamental physical chemistry properties of the melts, such as the thermodynamic properties of liquid steels containing high Mn and Al contents, the viscosity and thermodynamic properties of slags containing high MnO, as well as the viscosity and thermodynamic properties of slags containing low SiO2 and high Al2O3 contents, will be measured systematically. And then the models for predicting the physical chemistry properties will be established based on the experimental data. Furthermore, the kinetics of the reactions between slags and metals will also be investigated, and the reactions mechanism will be elucidated. The obtained results will offer theoretical principle for the optimization of the smelting process of low-density steels. Simultaneously, a number of fundamental data that are crucial to establish physical chemistry theory of the related metallurgical melts will be provided.. By using the high temperature viscometer designed and assembled by the present group, the viscosity of the slags will be measured under the controllable atmosphere. By adopting the liquid copper as reference metal, the thermodynamic activities of MnO, SiO2 and Al2O3 in the slags will be measured. By utilizing the immiscibility between liquid iron and liquid silver, the thermodynamic properties of liquid steels containing high Mn and Al contents will be determined through the chemical equilibrium method combined with the solid electrolyte electromotive force method. Finally, by the investigation of reaction kinetics between slags and liquid steels, the regulation of the transfer of Mn and Al between slags and liquid steels and the kinetic mechanism of the reaction will be clarified.

针对低密度钢冶炼涉及的冶金熔体的热物理和热力学数据匮乏、相关渣/金反应机理不明的问题，项目系统测定高Mn高Al含量钢液的热力学数据、高MnO含量熔渣及低SiO2高Al2O3含量熔渣的热力学性质和粘度数据。并根据实验数据建立相关熔体的粘度预报模型和热力学性质计算模型，探明相关渣/金反应的机理和动力学规律。所得成果，为低密度钢冶炼工艺优化提供所需的理论依据，也为相关熔体物理化学性质理论的建立提供重要的基础数据。. 采用课题组设计组装的高温粘度仪，在气氛可控的条件下，测定相关熔渣的粘度数据。以Cu液为参比金属相，测定相关熔渣中MnO、SiO2和Al2O3组元的活度数据。利用Ag液与Fe液的互不相溶性，通过Ag液和Fe液间的化学平衡，并结合固体电解质电动势法，测定高Mn、Al含量钢液的热力学数据。通过渣/金间反应动力学的研究，获得Mn和Al在渣/金间的迁移规律及反应机理。

本项目针对低密度钢冶炼涉及的冶金熔体热物理和热力学数据匮乏、相关渣/金反应机理不明等问题，系统测定了高Mn、高Al含量钢液的热力学数据、高MnO含量熔渣及低SiO2、高Al2O3含量熔渣的热力学性质和粘度数据，根据实验数据建立相关熔体的粘度预报模型和活度计算模型。此外，实验研究了低密度钢与普通熔渣和低反应性渣之间的反应行为，揭示了相关渣/金反应机理和动力学规律。.通过本研究：（1）获得了1573 K-1873 K时、氩气和CO:CO2=99:1的保护气氛下，不同碱度和MnO含量对MnO-CaO-SiO2-MgO-Al2O3熔渣粘度的影响规律；（2）获得了1598 K-1773 K时、氩气/氢气=4:1的保护气氛下，不同助熔剂对CaO-Al2O3-6%SiO2-5%MgO低密度钢保护渣粘度的影响规律；（3）获得了1873 K条件下，MnO-CaO-SiO2-(10%、20%、30%)Al2O3-5%MgO熔渣体系中MnO的活度，获得适用于高Mn渣中MnO活度的计算模型；（4）阐明了1873 K下Fe-Al-O熔体的中Al-O平衡行为，采用Wagner模型、UIP模型和R-K多项式对Al-O平衡进行分析计算，获得了Al、O间的活度相互作用系数以及Al、O的活度；（5）探明了1873 K条件下高Mn、Al含量的Fe-Mn-Al熔体中Mn和Al平衡行为，并采用Wagner模型和R-K多项式计算的得到了Mn和Al之间的活度相互作用系数，获得了Mn含量对Al活度的影响规律；（6）探究了高Al钢熔体与CaO-SiO2基和CaO-Al2O3基保护渣的反应行为，阐明了动态界面现象对反应的影响，并假设不同的控速环节，对反应动力学进行了分析。.研究所获成果为低密度钢冶炼工艺优化提供了所需的理论依据，也为相关熔体物理化学性质理论的建立提供了重要的基础数据。